262 
Beetles 
Fig. 359. — Larva 
of carrion-beetle, 
Silpha sp. (One 
and one-half times 
natural size.) 
the large shield-like prothorax yellowish with a black blotch in the center. 
In S. noveboracensis only the margin of the prothorax is yellow. 
The burying-beetles, Necrophorus, are large insects from an inch 
to an inch and a half long, with the body thick and parallel-sided. The 
commoner species have a pair of dull red transverse blotches on each elytron. 
In some species the prothorax and head are also marked 
with red. The common name comes from the well- 
known habit of these insects of digging underneath small 
dead animals, as mice or birds, until the corpse is in a 
hole; it is then covered over and thus really buried. 
The female lays her eggs on the corpse, and the larvae 
hatching from them feed on the decaying matter. These 
larvae have spiny plates on the back of the body and 
are otherwise unlike the Silpha larvae. Some Necrophorus 
larvae are predaceous and others feed on decaying vege¬ 
table matter. 
Most of the blind, pale cave-beetles found in caves in this country and 
Europe are Silphidae. 
The Cucujidae, with a name derived from the Portuguese Cucuyo, a 
large luminous Brazilian snapping-beetle or elater, of entirely different 
family, are a family of small beetles, with flattened reddish or light-brown 
body, whose outdoors haunts are mostly under the bark of trees. Sev¬ 
eral species, however, have learned that 
life in a granary is just as safe from pre¬ 
daceous enemies, and a thousand times 
safer from starvation. Of these sophisticated 
Cucujids, Silvanus surinamensis, the saw¬ 
toothed grain-beetle (Fig. 360), is the most 
familiar and injurious. The adult is about 
J inch long, flat and chocolate-brown, and 
may be distinguished from the other small 
beetles similarly attacking stored grain by 
the serrated margins of its prothorax. It 
infests dried fruits, nuts, seeds, and dry 
pantry stores of all sorts, as well as grain bins 
and cribs. The larvae (Fig. 360) are active 
little six-legged flattened whitish grubs which run about and nibble indus¬ 
triously. When full-grown the larva attaches itself by a gummy excretion 
to some object, and pupates. When living in light granular substances, 
as oatmeal, etc., a delicate case is constructed of the material in which to 
pupate. In summer the life-cycle from egg to adult requires but twenty- 
four days; in spring from six to ten weeks. Six to seven generations are 
Fig. 360. —Larva, pupa, and adult of 
the saw-toothed grain-beetle, Sib 
vanus surinamensis. (After How¬ 
ard and Marlatt; much enlarged.) 
